A Study On Block Stability In The Surrounding Rock Of Underground Cavities In Pushihe Pumped-Storage Power Station

The stability in the surrounding rock is an important problem in the design and construction of underground engineering. It is involved with tunneling, building up, investments, time limit for a project etc. So it should be received much recognition.Dissertation put Pushihe Pumped-Storage Power Station as the object of study. Base on the developmental feature of the exploratory heading structural plan,combining the underground factory building excavation programme and making use of stereographic projection,vector calculus,and the result of three-dimensional network,author carried on the analyse of the underground factory building free-face block hunting and stability.Study how to acquire the block exposed position,volume and the stability parameter. Generate program to carry out the whole research programmeing process. It will make the result be applied to the production more convenient and faster.First, introduced the engineering geology survey contained geographical position, stratigraphic lithologic characters, geological structure, hydrological geology, the feature of the crustal stress and geology engineering geology feature etc. of the underground factory building in Pushihe Pumped-Storage Power Station.Second, elborated the principle of the block and introduced the block class and define, pyramidal model, the mathematical representation spatial block, finiteness theorem, movability theorem, the cmplexor differentiate method of crack block, the cmplexor differentiate method of the block mobility and keyblocks discrimination etc.Third, according to the joint and fault material of exploratory tunnel, obtained the rock discontinuity surface dominance occurrence of the research area. Ascertain mechanics parameter of the structural plane.Establishing the jointrock geology model of underground factory building.During the process, divided four the main set of joints, the occurrence of the first main set of joints: the dips is 117.6°,the dips angle is 57.8°; the occurrence of the second main set of joints: the dips is 59.0°,the dip angle is 61.1°; the occurrence of the third main set of joints:the dips is 279.1°,the dip angle is 70°; the occurrence of the forth main set of joints:the dips is 276.1°,the dip angle is 31.3°. Devided two the main set of faults.the occurrence of the first main set of faults: the dips is 118.6°, the dip angle is 65.2°. the occurrence of the second main set of faults: the dips is 59°,the dip angle is 66°.Base on it , carried on analysing of the underground factory tunnels block theory by stereographic projection and complexor method.Finally, maked use of three-dimensional joint network technic to create joint three-dimensional network model.Through measuring the development feature of the fault, create the space geometric model of the faults.Make use of the computer program,cutted the space geometric model,. Then it formed the path picture of the joint and fault on the free-face of underground factory building. Subsequently, through acquiring the structural plane path picture of free-face on the underground factory building, search the closepolygon on the free-face and carry on distinguishing of space geometric. Then it can calculate vertex coordinate, gravity coordinate, volumn, weight, glide type, stability coefficient and residual glide force of the block.We can aquire the possible destabilizing block on excavation space.During the process,we can get block which stabilized coefficient less-than 3.0.It contained the 69 block of Main Factory Building,the 5 block of Auxiliary Plant, the 40 block of Unloading Bay,the 25 block of Main Transformer House.We can also aquire the block stabilize coefficient less-than 1.0.It contained the 25 block of Main Factory Building,the 1 block of Auxiliary Plant, the 24 block of Unloading Bay, the 10 block of Main Transformer House;Cutting and hunting the model of the faults, we can get block which stabilized coefficientless-than 3.0.It contained the 2 block of Main Factory Building,the 1 block of Auxiliary Plant, the 2 block of Unloading Bay, the 1 block of Main Transformer House.We can also aquire the block stabilize coefficient less-than 1.0.the 1 block of Main Transformer House only.We can know that the Main Factory Building and the Main Transformer House have the much bigger room and free-face area that is advantage to format keyblocks by comparing exposed situation of keyblocks.In comparison, the former formed much more keyblocks than the latter.Because the former cavity breadth is bigger.The Main Factory Building's left side wall have much more area than right,so it can form much more keyblocks.However the Main Transformer House's right side wall have much more keyblocks than left,so the right side wall can form much more keyblocks easily. Then design shotcreting, systematic bolts, ejector anchor and locality anchor's coefficient.Finally, evaluated and analysed the stability of the block under the action of deadweight and shotcreteblot supporting.For being adapt to the actual production and providing a sort of pass for researching the underground cavities, author applied c++builder to settle this problem.Introduced program flow, software interface and method of operation in related chapter, and the software will make the production more practicality, the operation more convenient and the result more visualized in scientific research and production.Thoughts the block search and stabilization calculation of the Pushihe Pumped-Storage Power Station.Not only analyse the adjacent rock stability of underground excavations, but also supply scientific foundation for the later design and construction..At the same time, supply the effective analysis method on block stability in the surrounding rock of the underground cavities also.